The present invention relates generally to cable management systems and particularly to cable management in a stationary system linked to a dynamic system.
Interface cables are used to connect stationary systems to dynamic systems in many types of devices, such as in automated manufacturing devices, mass storage devices, and so forth. However, when a cable has excess slack or is otherwise uncontrolled, it may twist, flap or become entangled, causing the moving system to function improperly. Furthermore, cable life is shortened when its movements are uncontrolled, since it is flexing and bending in an inconsistent manner. For example, if the bend radius of the cable is too tight, wires within the cable can wear out or break. Also, since loose cables take up more room than managed cables, the device itself must be made larger to accommodate these cables. Partial control of cables, such as accumulating a cable in a separate chamber also does not solve the problem, as the cable is still subject to random movements that can include contacting an outer wall of the chamber. In addition to reducing precision operation of the dynamic system, such contact can also cause wearing of cable insulation.
In mass storage devices, for example, ribbon cables connect stationary electronics to electronics on moving assemblies, such as a pivot assembly and a lift assembly. Together, these assemblies are used to position a robotic device, i.e., a media transport assembly (MTA), to retrieve the desired media from storage. Uncontrolled slack in the ribbon cables, however, causes bending and flexing of the cables during operation. This flexing can cause the cables to catch on protrusions within the chassis, interfere with sensor operation, bend too tightly, wear out, and so forth. Furthermore, during pivoting of the pivot assembly, backlash can occur, i.e., movement or play in gear teeth alignment, which also reduces the resolution and repeatability in positioning of the MTA.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for providing improved cable management in a dynamic system linked to a stationary system.
A cable management system comprising a cable flex radius system having at least two opposing curved surfaces to control flex radius of a cable linking a stationary system to a dynamic system is disclosed. The cable management system also comprises a cable strain relief system comprising a cable clamp located on each of the at least two opposing curved surfaces. The system simultaneously provides positional control of the cable and biased backlash of the gears in the dynamic system. The system insures consistent cable bend radius and slack management required to insure flex cable cycle life.
In one embodiment, the cable management system is comprised of a torsion arm and a spool. In this embodiment, the torsion arm pivots during rotation of the spool. A spring connected to the torsion arm provides the requisite tension force to a cable that links the spool and the torsion arm. In this way, cable movement is controlled not only during operation of a moving mechanism, but also while the mechanism is at rest. Such control is particularly useful in devices which require precise movements, such as media storage devices.
The components comprising the cable management system are simple and inexpensive, thus factory installation specifications are easy to maintain. As a result, an additional advantage of the present invention includes the ability to easily retrofit manufactured devices with the cable management system.